Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/10—Protecting distributed programs or content, e.g. vending or licensing of copyrighted material ; Digital rights management [DRM]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
  • H04N21/83—Generation or processing of protective or descriptive data associated with content; Content structuring
  • H04N21/835—Generation of protective data, e.g. certificates
  • H04N21/8358—Generation of protective data, e.g. certificates involving watermark
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/70—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer
  • G06F21/82—Protecting input, output or interconnection devices
  • G06F21/84—Protecting input, output or interconnection devices output devices, e.g. displays or monitors
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
  • H04N21/4302—Content synchronisation processes, e.g. decoder synchronisation
  • H04N21/4307—Synchronising the rendering of multiple content streams or additional data on devices, e.g. synchronisation of audio on a mobile phone with the video output on the TV screen
  • H04N21/43074—Synchronising the rendering of multiple content streams or additional data on devices, e.g. synchronisation of audio on a mobile phone with the video output on the TV screen of additional data with content streams on the same device, e.g. of EPG data or interactive icon with a TV program
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/45—Management operations performed by the client for facilitating the reception of or the interaction with the content or administrating data related to the end-user or to the client device itself, e.g. learning user preferences for recommending movies, resolving scheduling conflicts
  • H04N21/462—Content or additional data management, e.g. creating a master electronic program guide from data received from the Internet and a Head-end, controlling the complexity of a video stream by scaling the resolution or bit-rate based on the client capabilities
  • H04N21/4627—Rights management associated to the content
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
  • H04N21/83—Generation or processing of protective or descriptive data associated with content; Content structuring
  • H04N21/835—Generation of protective data, e.g. certificates
  • H04N21/8355—Generation of protective data, e.g. certificates involving usage data, e.g. number of copies or viewings allowed
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
  • H04N21/85—Assembly of content; Generation of multimedia applications
  • H04N21/854—Content authoring
  • H04N21/8547—Content authoring involving timestamps for synchronizing content
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/765—Interface circuits between an apparatus for recording and another apparatus
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/162—Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
  • H04N7/163—Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing by receiver means only
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/14—Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
  • G09G5/003—Details of a display terminal, the details relating to the control arrangement of the display terminal and to the interfaces thereto
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
  • H04N2005/91335—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a watermark
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/84—Television signal recording using optical recording
  • H04N5/85—Television signal recording using optical recording on discs or drums

Definitions

• the present invention relates generally to a method and system for controlling the use of unauthorized content, and specifically for controlling the display of content that is marked as "copy-never.”
• a display device is prevented from displaying content marked as copy-never, unless the content is received within a specified amount of time from that indicated by a time-of-play indicator.
• the time-of-play and copy-never indicators may be securely embedded in the content using any suitable method known in the art, for example, encryption or watermarking.
• a display device comprises a television, computer monitor, personal data assistant (PDA), or similar device of any suitable construction that further comprises, without limitation, a cathode-ray tube, an LCD, or a gas plasma display.
• a display device additionally includes systems for reading time-of-play and copy-never indicators, determining a current time, and handling the video signal according to the status of those indicators. For example, if the time between when content is transmitted and when it is received exceeds a defined maximum amount of time, the display device may be configured to prevent or interfere with display of the received content.
• the display device may be configured to prevent or interfere with display of the received content if the receiving apparatus does not receive an indication of when the content was transmitted when it otherwise knows that such mark should be present, evidence of tampering.
• the display device may be provided with systems for determining a current time that is synchronized with the signal source (e.g., a media player, broadcaster, or other source of the video signal) that embeds the time-of-play indicator in the video signal.
• the display device is able to synchronize with the signal source by periodically communicating with the signal source using a separate communication line, such as a telephone line.
• synchronization may be accomplished in any other suitable fashion, such as by communicating over the same connection used for the video signal, or both having devices (the display device and the signal source) obtain a current time from a third- party timekeeper.
• a third-party timekeeper Various third-party sources of reliable time are known in the art.
• the present invention provides a system and method for preventing the display of unauthorized copies of recorded content on compliant display systems. Operation of the method may further be illustrated by the following example. As an initial step, a media player or other source of a video signal may determine whether particular content is marked as copy-never.
• the media player may insert a secure indicator, such as a watermark, into the video signal.
• the secure indicator may indicate that the video signal is copy- never content, or originated from copy-never content.
• the secure indicator may include a mark or timestamp indicating the current time and date, which may be obtained from an internal or external clock, or in the alternative, the current time and date may be inserted in a second secure indicator embedded in the video signal. Time and date may be recorded in any suitable time format.
• the display device may determine whether the video signal contains a copy-never indicator.
• the display may also determine whether the video signal contains a time-of-play indicator. If detected, the display device compares the time-of-play indicator with the time obtained from an independent source, such as an internal or external clock, and determines a time lag. If the time lag exceeds a defined maximum, the display device prevents normal display of the content, or completely prevents display of the video signal. Thus, for example, if the video signal originated from a compliant media player directly connected to a compliant display device and playing an authorized copy of media content, the content would display normally because it would contain the required secure indicators, and the time lag measured by the display device would not exceed the defined maximum.
• an independent source such as an internal or external clock
• the otherwise compliant video signal was copied and later transmitted to the compliant display device, this would introduce a time lag that would likely exceed the maximum permissible lag, preventing normal display of the video signal.
• the otherwise compliant video signal was transmitted to a remote display device not authorized for use of the content, depending on the remoteness of the receiving device this would also introduce a time lag measurably greater than would be expected for transmission to a nearby display device.
• video signals from non- compliant sources these can be identified as such and prevented from normal play by compliant display devices.
• the maximum permissible time lag may vary depending on the network over which the video signal is permitted to be transmitted.
• the granularity of the secure time could be on the order of minutes or even tens of minutes. In the case of protection against unauthorized remote viewing, the granularity of the secure time could be on the order of milliseconds or less to distinguish between transmission latencies for direct analog connections or local area network digital connections and wide area network digital connections. For example, if redistribution is only permitted over a direct connection, the expected time lag may approach the cable length divided by the speed of light.
• Other transmission networks, for example the Internet should introduce easily detectable delays in comparison to a relatively short direct connection, such as cables routed within a single home or apartment.
• a statistically significant difference in transmission time between distribution over a local area network, and distribution to a distance device over a wide area network may be characterized by one of ordinary skill, and used as a basis for determining a maximum acceptable time lag.
• the length of a maximum acceptable delay may depend on the business model used for distribution of the content in question. For example, a time lag on the order of about 1-1000 ms, such as about 7 ms, may be useful to restrict distribution to near-instantaneous viewing within a close physical proximity. On the other hand, longer delays may prove useful for content distributed under business models that allow for reasonable pausing of content.
• Fig. 1 is a diagram showing an exemplary system for controlling the display of content according to the invention.
• Fig. 2 is a flow diagram showing exemplary steps of a method for controlling the display of content.
• Fig. 3 is a flow diagram showing exemplary steps of an alternative method for controlling the display of copy-never content.
• Fig. 4 shows an exemplary rogue device for circumventing a copy-protection system according to the invention.
• Fig. 5 shows exemplary steps of a method for circumventing a system for preventing normal display of an unauthorized video signal.
• Fig. 6 shows exemplary steps of a method for circumventing a system for preventing normal display of an unauthorized video signal.
• Fig. 1 shows a system 100 for preventing normal display of a received video signal that is not authorized for use at a display device.
• System 100 comprises signal sources 102 and 104 provided on a network 106 such as the Internet, and a compliant display device 108 operatively coupled to the network 106.
• Digital content such as a video or audio signal intended for a media driver may be vulnerable to being intercepted and stored on a storage device 107 as it passes through the unknown network.
• the signal may emerge from the network 106 and arrive at multiple display devices at different times. Without some method of determining whether the video or audio signal has been duplicated or sent off to a prohibited remote location, even a copyright management-compliant source device may be caused to operate in an unauthorized fashion.
• Signal sources 102 and 104 are intended to be illustrative, and not limiting, as to the specific types of devices employed.
• Display device 108 may be operatively connected to signal source 102 or 104 through the network 106, utilizing any suitable hardware or software system equipment as known in the art.
• Signal source 102 processes copy-never content that is prerecorded on media 110, such as a DVD, to generate a video signal.
• Signal source 102 comprises a secure time source 112 and an encoder 114 such as a watermark inserter for embedding a secure timestamp in the video signal.
• Other suitably robust systems known in the art, such as the use of VEIL marks, may be used to reliably embed the secure timestamp or other information in the video signal.
• signal source 104 broadcasts a video signal generated from a live video source 116.
• Signal source 104 comprises a secure time source 118 and an encoder 120 such as a watermark inserter for marking or embedding a secure timestamp in the video signal.
• Encoder 120 may also be configured to embed a copy- never indicator into the video signal.
• the video signal is marked in real-time, or near real-time, as to prevent introducing noticeable delay into the transmission of the video signal.
• Any suitable hardware or software system may be used to embed the information in the video signal, in real-time or otherwise, as is known in the art.
• signal source 104 may broadcast a prerecorded video signal already marked as copy never, thereby alleviating the need for encoder 120 to embed a copy- never indicator into the video signal. In such case, only the timestamp need be inserted at the time of broadcast.
• Display device 108 comprises a detector 122, comparator 124, secure time source 126, display driver 128, and display 130.
• Detector 122 and display driver 128 are operatively connected to network 106 for receiving the video signal containing the watermark. Detector 122 detects the copy-never indicator and the secure timestamp embedded in the video signal. Detector 122 is operatively connected to a comparator 124, and provides information from the secure timestamp to the comparator 124. Comparator 124 is also operatively connected to a secure time source 126 and to display driver 128. Comparator 124 compares the secure timestamp with the time indicated by the secure time source 126.
• comparator 124 sends a signal to display driver 128 to disable or modify the display of the content.
• the display may scramble the content or blank the screen.
• the display driver may display a message on the screen indicating a problem with authorization has been detected.
• Other configurations to ultimately prevent the normal display of a received video signal besides disabling the display driver may also be suitable, and one of ordinary skill may readily implement such configurations using any known circuitry or programming language.
• comparator 124 may send a signal to display driver 128 to enable display driver 128. In the alternative, the comparator 124 may not send a signal to display driver 128 if the state (enabled or disabled) of display driver 128 does not need to change. For example, if display driver 128 is enabled, the absence of a signal from the comparator 124 may result in normal processing of the video signal by driver 128.
• Fig. 2 shows exemplary steps of a method 200 for preventing the normal display of an unauthorized video signal in conjunction with elements of system 100. Other or different steps may also be suitable, and one of ordinary skill may readily implement such steps using any suitable programming languages and methods.
• display device 108 Being configured to accept signals from compliant signal sources, at step 202, display device 108 receives a video signal. At step 204, display device 108 determines whether a secure timestamp is associated with the video signal. Data such as a secure timestamp may be associated with or embedded in a video signal as is known in the art. For example, a timestamp may be placed in a vertical blanking interval, or in a video watermark. For further security, the timestamp may be encrypted using a known method, and decrypted by the receiving device.
• a secure timestamp is not detected ("N" at step 204)
• normal display of the video signal may be prevented at step 208 if the system otherwise, using known methods including a priori knowledge or context, determines that such a mark should have been embedded in the video signal. If a secure timestamp is detected ("Y" at step 204), the lag between the video signal being transmitted by video source 102, for example, and display device 108 is calculated at step 206. If the lag is less than or equal to a defined maximum ("Y" at step 206), then normal display of the video signal may be allowed at step 210. If the lag is greater than a defined maximum ("N" at step 206), then normal display of the video signals may be prevented at step 208.
• FIG. 3 shows exemplary steps of a method 300 for preventing the normal display of unauthorized copy-never content in conjunction with elements of system 100.
• Method 300 makes use of a timestamp in a manner similar to method 200, and in addition, checks for a copy-never indicator which is used to trigger authorization conditions partially different from method 200.
• display device 108 receives a video signal.
• display device 108 determines whether the video signal has associated content usage right management information. If no content usage rights management information is detected ("N" at step 304), then normal display of the video signal may be prevented at step 312, if the system otherwise determines ("Y" at step 305), using known methods including a priori knowledge or context, that such a mark shoui ⁇ nave Deen embedded in the video signal.
• display device 108 may determine whether copies of the video signal are allowed at step 306. If copies are allowed ("Y” at step 306), then normal display of the video signal may be allowed at step 314. If copies are not allowed ("N” at step 306), then display device 108 determines whether a secure timestamp is associated with the video signal at step 308. If a secure timestamp is not detected (“N” at step 308), then normal display of the video signal may be prevented at step 312, again subject to a determination ("Y" at step 305) that a timestamp should have been embedded in the video signal.
• the lag between the video signal being transmitted by video source 102, for example, and display device 108 may be calculated at step 310. If the lag is less than or equal to a defined maximum ("Y" at step 310), then normal display of the video signal may be allowed at step 314. If the lag is greater than a defined maximum ("N" at step 310), then normal display of the video signals may be prevented at step 312.
• this invention may be used as a controlling function for any time of communication or transaction that is confined in time.
• the invention can be applied not only to display devices, but to any other systems for controlling the function of any type of communication or transaction that is confined in time.
• any content protection scheme may be circumvented by a determined infringer.
• Systems and methods for circumventing the present invention may include, for example, inserting a rogue copying device upstream of a compliant display device.
• the rogue device may be configured to masquerade as a compliant receiving device, a compliant source device, or both.
• the rogue device may appear to be a compliant source.
• a compliant source device for example a DVD player
• the rogue device may appear to be a compliant receiving device.
• a rogue device that mimics both compliant source and compliant display behavior may be designed based on an analysis of compliant devices. And even if operational characteristics of the compliant devices have been effectively prevented from being discovered by inspection and analysis, information for overcoming a device's security features may be misappropriated. It should be apparent, therefore, that creation of a rogue device should be considered a possibility, even when stringent security measures have been used to prevent it.
• Fig. 4 shows a rogue circumvention device 402 disposed in a system 400 of compliant devices designed to prevent the display of unauthorized video signals.
• Fig. 4 is similar to Fig. 1, in that compliant receiving device 404 of Fig. 4 parallels compliant display device 108 of Fig. 1, compliant source device 406 of Fig. 4 parallels signal source 102 or 104 of Fig.
• Rogue device 402 comprises a watermarking device 408 and a storage device 410.
• Storage device 410 is operatively connected to compliant source device 406 through a network, for example, for receiving a video signal containing a watermark.
• Storage device 410 is also operatively connected to watermark device 408.
• the use of watermark device 408 is intended to be illustrative, and not limiting. Other known devices may be employed as appropriate, depending on the copy-protection scheme implemented in system 400. Thus, watermark device 408 would be appropriate to identify the timestamp and/or the content usage rights management information embedded as a watermark in the video signal.
• Watermark device 408 may adjust the timestamp to the time, or approximate time, that rogue device 402 transmits the video signal to the operatively connected compliant receiving device 404.
• the purpose of the modifying the timestamp is to remove the transmission delay that may be caused by the rogue device's interception of the video signal, and thereby allow for the normal display of the video signal by a compliant display device.
• watermark device 408 may modify the content usage rights management information to change any copy-never indicator to copy-once or copy-freely, for example.
• Such modification of the content usage rights management may be effective in the case that system 400 allows the normal display of a video signal that is "copy-allowable” (or not copy-never) regardless of the timestamp associated with the video signal.
• Storing of the received content allows rogue device 402 to transmit a "modified" video signal at an indeterminate time after receiving the video signal from compliant source device 406.
• rogue device 402 may output the video signal from storage device 410 to watermarking device 408 to modify the embedded timestamp and/or content usage right management information for transmission to any compliant receiving device.
• Any suitable storage device may be used to store the received content as is known in the art.
• a hard drive, tape drive, CD, DVD, or random-access or flash memory may be used.
• a hard drive, tape drive, CD, DVD, or random-access or flash memory may be used.
• rogue device 402 receives content from a compliant source device 406 at step 502, and stores the content for later distribution to compliant or non- compliant display devices at step 504.
• the rogue device 402 replaces the original timestamp with a new timestamp bearing the time, or approximate time, of retransmission to a receiving device at step 506.
• rogue device 402 may then transmit the modified content to compliant receiving device 404. Therefore, even if the receiving device is compliant with the methods disclosed herein, it may not be able to discern the true time lag from the original compliant content source and thus display the content normally.
• rogue device 402 may alter the content usage rights management information in the content. For example, a rogue device might change a "copy-never" indicator to "copy freely.”
• Fig. 6 shows exemplary steps of a method 600 for circumventing a system for preventing the normal display of unauthorized video signal in conjunction with elements of system 400.
• rogue device 402 receives content from a compliant source device 406 at step 602, and stores the content for later distribution to compliant or non-compliant display devices at step 604.
• rogue device 402 may replace a "copy-never" indicator with a "copy-freely” indicator.
• the step at which the content is stored may vary. For example, rogue device 402 may copy the content after the content usage rights management information has already been modified.
• rogue device 402 may then transmit the modified content to compliant receiving device 404. Therefore, even if the receiving device is compliant with the methods disclosed herein, it may determine that the received content is authorized from the original compliant content source, and thus display the content normally.
• a timestamp might consist of easily identified bits in a vertical blanking interval, while content usage rights management information may be placed in a watermark that is more difficult to read or alter.
• rogue device 402 may be configured to alter a minimal amount of information that is most readily accessed to circumvent the content protection methods disclosed herein. Any of these various circumvention methods, and systems for performing them, should also be considered within the scope of the invention.

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Computer Security & Cryptography (AREA)
• Theoretical Computer Science (AREA)
• Computer Hardware Design (AREA)
• Software Systems (AREA)
• General Physics & Mathematics (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Databases & Information Systems (AREA)
• Technology Law (AREA)
• Television Signal Processing For Recording (AREA)
• Storage Device Security (AREA)
• Signal Processing For Digital Recording And Reproducing (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
• Television Systems (AREA)

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• 2004
  • 2004-12-06 WO PCT/US2004/040862 patent/WO2005057356A2/en active Application Filing
  • 2004-12-06 EP EP04813211A patent/EP1695184A4/en not_active Withdrawn
  • 2004-12-06 US US11/006,063 patent/US7454019B2/en not_active Expired - Fee Related
  • 2004-12-06 KR KR1020067012663A patent/KR100907121B1/ko not_active IP Right Cessation
  • 2004-12-06 CN CNA2004800403488A patent/CN1954608A/zh active Pending
• 2008
  • 2008-11-17 US US12/272,621 patent/US20090136029A1/en not_active Abandoned

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